Djivoh Y1, De Jaeger D1
1UCL, Institut of Neuro-Sciences (IONS), Laboratoire de Biomécanique et Physiologie de la Locomotion, Faculté des Sciences de la Motricité, Louvain-la-Neuve, Belgium
Background: Abdominal muscles become weak in postpartum which increases the risk of low back pain and pelvic floor disorders. To strengthen them, Crunch (lifting the trunk until the top of scapula is just off) and Hypopressive Abdominal Gymnastics (HAG, draw the belly in=phase-1, followed by diaphragmatic aspiration=phase-2) can be used. However, the already published literature does not allow to recommend one exercise for the postpartum abdominal management. Few data exist on the abdominal muscles activation during Crunch and HAG. Our question is: which exercise can activate all abdominal muscles?
Purpose: This study aimed to measure the activation of all abdominal muscles during the Crunch, the HAG and various combinations of Crunch and HAG.
Methods: We measured rectus abdominis (RA), external oblique (EO), internal oblique (IO) and transversus abdominis (TA) activity during four movements: Crunch, Drawing-in-Crunch (draw the belly in and add Crunch), HAG and HAG-Crunch (do HAG and add Crunch). Twenty-two nulliparous (aged between 19 and 22), and 19 women (who had given birth since 3 months to 20 years, aged between 28 and 54) participated in the study. We measured with electromyography, firstly the activity during reference movements (maximum voluntary contraction: MVC) and secondly the activity during the four movements mentioned above. This activity was expressed in percentage of MVC. For each muscle, the EMG activity was compared between groups and between movements using a two-way ANOVA test with repeated measures for movements. Post-hoc with Bonferroni test was used to locate the difference between the movements. The significant level was set at p 0.05.
Results: For each muscle, a significant movement effect was observed. The RA was more activated (p 0.001) during Crunch (49% of MVC) than during other movements (32% during Drawing-Crunch, 23% during HAG-Crunch and 3% during HAG). The EO (44%), IO (56%) and TA (99%) were more activated during Drawing-in-Crunch than during other movements (p=0.001). No difference between TA activity during Crunch (66%) and HAG (71% in phase-1 and 53% in phase-2). The group effect was significant for EO activity: women who had given birth activated more EO to perform Crunch (p 0.001). No interaction between movements and groups was observed for any muscles.
Conclusion(s): The HAG activated principally the TA. Other movements activated all abdominal muscles: the Crunch activated equitably all abdominal muscles, the Drawing-in-Crunch and HAG-Crunch provided more activation of TA but not of RA. Long-term effect of a training program focused on Crunch must be measured.
Implications: The Crunch would be effective in the strengthening of all abdominal muscles. Other aspects such as its effect on intra-abdominal pressure and pelvic floor should be considered.
Keywords: Abdominal exercises, Electromyography, Postpartum
Funding acknowledgements: We thank the women who participated in this study. Funding source: None.
Purpose: This study aimed to measure the activation of all abdominal muscles during the Crunch, the HAG and various combinations of Crunch and HAG.
Methods: We measured rectus abdominis (RA), external oblique (EO), internal oblique (IO) and transversus abdominis (TA) activity during four movements: Crunch, Drawing-in-Crunch (draw the belly in and add Crunch), HAG and HAG-Crunch (do HAG and add Crunch). Twenty-two nulliparous (aged between 19 and 22), and 19 women (who had given birth since 3 months to 20 years, aged between 28 and 54) participated in the study. We measured with electromyography, firstly the activity during reference movements (maximum voluntary contraction: MVC) and secondly the activity during the four movements mentioned above. This activity was expressed in percentage of MVC. For each muscle, the EMG activity was compared between groups and between movements using a two-way ANOVA test with repeated measures for movements. Post-hoc with Bonferroni test was used to locate the difference between the movements. The significant level was set at p 0.05.
Results: For each muscle, a significant movement effect was observed. The RA was more activated (p 0.001) during Crunch (49% of MVC) than during other movements (32% during Drawing-Crunch, 23% during HAG-Crunch and 3% during HAG). The EO (44%), IO (56%) and TA (99%) were more activated during Drawing-in-Crunch than during other movements (p=0.001). No difference between TA activity during Crunch (66%) and HAG (71% in phase-1 and 53% in phase-2). The group effect was significant for EO activity: women who had given birth activated more EO to perform Crunch (p 0.001). No interaction between movements and groups was observed for any muscles.
Conclusion(s): The HAG activated principally the TA. Other movements activated all abdominal muscles: the Crunch activated equitably all abdominal muscles, the Drawing-in-Crunch and HAG-Crunch provided more activation of TA but not of RA. Long-term effect of a training program focused on Crunch must be measured.
Implications: The Crunch would be effective in the strengthening of all abdominal muscles. Other aspects such as its effect on intra-abdominal pressure and pelvic floor should be considered.
Keywords: Abdominal exercises, Electromyography, Postpartum
Funding acknowledgements: We thank the women who participated in this study. Funding source: None.
Topic: Human movement analysis; Women's & men's pelvic health; Musculoskeletal: spine
Ethics approval required: Yes
Institution: Université Catholique de Louvain (UCL) - Belgium
Ethics committee: Comité d'étique Hospitalo-facultaire
Ethics number: 0032 027645514
All authors, affiliations and abstracts have been published as submitted.
